An X-ray computer tomographic device (hereinafter referred to as “X-ray CT device”) irradiates X-rays toward a subject and also detects the X-rays that have passed through the subject. As a result, projection data composed of the X-ray absorption coefficient inside the subject is obtained.
Among X-ray CT devices, there are multi-tube X-ray CT devices with multiple X-ray tubes (i.e., X-ray tube devices). Such X-ray devices are capable of generating two different X-ray images with a single scan by exposing two X-rays with different energies in alternation. However, a multi-tube X-ray CT device requires in which multiple X-ray tubes is included, and as a result, the device scale increases and the manufacturing cost also increases.